Ken Livingstone, London's mayor, has been advised by Bob Kiley, his £250,000 a year transport commissioner, to abandon his controversial congestion charging plan, or risk defeat in the next mayoral election.

Senior advisers to Mr Kiley revealed yesterday he has told Mr Livingstone that it is a high risk strategy which could rebound on him when he seeks re-election in 2004. Mr Kiley's advisers stressed that he was adopting a pragmatic attitude and that he fully supported the plan.

Mr Kiley's view is that there is no chance that the congestion plan under which motorists will pay £5 a day to drive into central London will be introduced by February 2003, because the charging technology will not be ready.

The scheme is already unpopular with several inner London boroughs. Mr Livingstone has already started drawing up a list of exemptions, including public sector workers such as hospital staff.

The scheme has been calcu lated by the mayor to raise £200m a year from motorists, to be spent on public transport improvements in London.

But Mr Kiley's advice is that hostile Londoners will not have the chance to witness any significant improvements before the next mayoral election.

His advice is that Mr Livingstone should make sure that he can point to a significant improvement in public transport before launching congestion charging, and that he should concentrate on improving the Underground with whatever scheme the government allows him to operate.

Mr Livingstone had a private meeting with Stephen Byers, the transport secretary, yesterday. It was later described by the transport department as "a regular event".

Several ministers would be happy if Mr Kiley convinced Mr Livingstone of the wisdom of deferring congestion charging. John Spellar, Mr Byers' deputy, considers that the plan could be an electoral liability not only for Mr Livingstone, but for London Labour MPs as well.